DYLAN SCOTT – APRIL 16, 2014, 9:49 AM EDTStates that have embraced Obamacare have also seen a significantly larger drop in their uninsured population, according to a Gallup poll released Wednesday.

In states that expanded Medicaid and actively participated in their insurance marketplace under the law, the uninsured rate dropped 2.5 percentage points, from 16.1 percent in 2013 to 13.6 percent in the first quarter of 2014.

But in states that did not expand Medicaid or participate in their insurance marketplace, the uninsured rate dropped only 0.8 percentage points, from 18.7 percent in 2013 to 17.9 percent in the first quarter of 2014.

"The states that have implemented two of the law's core mechanisms ... are realizing a rate of decline that is substantively greater than what is found among the remaining states that have not done so," Gallop wrote. "Consequently, the gap that previously existed between the two groups has now expanded."

Nationally, the uninsured rate has fallen from 18 percent before Obamacare enrollment launched in October to 15.6 percent in the first quarter of 2013.

The 2013 figures are based on a yearlong survey of 178,068 U.S. adults. The 2014 figures are based on a survey, conducted from January through March, of 43,562 U.S. adults.